Stabilizers are often used in polymeric compositions, e.g., polyolefins, polyvinyl halides, polyesters, polyamides, nitrile polymers, styrenic polymers and acrylate polymers and elastomeric materials such as butadiene rubber, polyisoprene etc to stabilize the polymeric compositions against the effects of heat and light degradation. Exemplary of such stabilizers are phenolic antioxidants, hindered amine light stabilizers, ultraviolet light absorbers, phosphite antioxidants, metal salts of fatty acids, hydrotalcites, metal oxides, epoxidized oils, hydroxylamines, amine oxides, lactones, and thiosynergists. In particular, organic phosphites have been used as antioxidants, e.g., secondary antioxidants, for polyolefins, polyvinyl chloride, and elastomers. Examples of such phosphites are disclosed in H. Zweifel (Ed) Plastics Additives Handbook, 5th edition, Hanser Publishers, Munich 2000.
Phosphite stabilizers, both liquid and solid, are known in the art. Many of the most effective organic phosphites are solids at ambient temperature and accordingly do not lend themselves to being processed with certain polymers, and in particular, with low melting point polymers. Owing to their solid form and concomitant processing limitations, for example, some solid alkylaryl phosphites have been demonstrated to plateout during processing in some plastics, in particular low melting point plastics, and form deposits on processing machinery surfaces. In addition, solid organic phosphites typically must be processed, e.g., heated and melted, in order to be incorporated into the respective polymer compositions thereby increasing handling and processing costs.
One of the most widely used solid organic phosphites is tris(2,4-di-t-butylphenyl)phosphite, which is commercially sold under the trade name Alkanox® 240 (Chemtura Corporation, Middlebury, Conn., USA). Tris(2,4-di-t-butylphenyl)phosphite has some processability and solubility limitations, however, owing to its solid form. U.S. Pat. No. 5,254,709, the entirety of which is incorporated herein by reference, describes the synthesis of tris(2,4-di-tert-butyl)phenyl phosphite by reacting an alkylated phenol intermediate, i.e., 2,4-di-tert-butyl phenol, with phosphorus trichloride in the presence of catalyst according to the following reaction:

Liquid phosphite compositions are also well known and do not possess the handling problems associated with solid phosphite compounds. In addition, liquid phosphite compositions generally exhibit better processability than solid phosphite compositions for polymers that process at low temperatures. Tris(p-nonylphenyl)phosphite (TNPP), for example, is one alkylaryl phosphite that is a stable liquid at ambient conditions.
TNPP is a versatile phosphite stabilizer that is useful in stabilizing a large number of polymers such as HDPE, LLDPE, SBR, ABS, PVC and others. There is, however, a need to replace TNPP owing to the alleged estrogenicity of nonylphenol, which is used in the manufacture of TNPP.
Thus, the need exists for novel alkylaryl phosphite compositions that are liquids at ambient conditions while not having the perceived estrogenicity concerns associated with nonylphenol and having the ability to effectively stabilize polymer resins and compositions against heat and light degradation. The need also exists for methods for producing such phosphite stabilizers, to novel alkylated phenolic intermediates for forming such phosphite stabilizers, and to processes for forming such novel alkylated phenolic compositions.